Not entirely sure why this never came up when I originally tested this (maybe some BIOSes already have this setup?) but the ->caps_init vfunc appears to cause the display engine to throw an exception on driver init, at least on my ThinkPad P72:

nouveau 0000:01:00.0: disp: chid 0 mthd 008c data 00000000 0000508c 0000102b

This is magic nvidia speak for "You need to have the DMA notifier offset programmed before you can call NV507D_GET_CAPABILITIES." So, let's fix this by doing that.

Signed-off-by: Lyude Paul lyude@redhat.com Fixes: 4a2cb4181b07 ("drm/nouveau/kms/nv50-: Probe SOR and PIOR caps for DP interlacing support") Cc: stable@vger.kernel.org # v5.8+ --- drivers/gpu/drm/nouveau/dispnv50/core507d.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/dispnv50/core507d.c b/drivers/gpu/drm/nouveau/dispnv50/core507d.c index ad1f09a143aa4..c984080ce99f2 100644 --- a/drivers/gpu/drm/nouveau/dispnv50/core507d.c +++ b/drivers/gpu/drm/nouveau/dispnv50/core507d.c @@ -80,11 +80,19 @@ core507d_caps_init(struct nouveau_drm *drm, struct nv50_disp *disp) struct nvif_push *push = disp->core->chan.push; int ret;

- if ((ret = PUSH_WAIT(push, 2))) + if ((ret = PUSH_WAIT(push, 4))) return ret;

+ PUSH_MTHD(push, NV507D, SET_NOTIFIER_CONTROL, + NVDEF(NV507D, SET_NOTIFIER_CONTROL, MODE, WRITE) | + NVVAL(NV507D, SET_NOTIFIER_CONTROL, OFFSET, NV50_DISP_CORE_NTFY >> 2) | + NVDEF(NV507D, SET_NOTIFIER_CONTROL, NOTIFY, ENABLE)); PUSH_MTHD(push, NV507D, GET_CAPABILITIES, 0x00000000); - return PUSH_KICK(push); + ret = PUSH_KICK(push); + if (ret) + return ret; + + return 0; }

int